| 摘要 |
PROBLEM TO BE SOLVED: To provide a multi-row combination angular contact ball bearing that achieves stable high-speed rotation without causing a seizure fault in inner bearings.SOLUTION: Among front bearings 40, 50, 60, and 70, ball pitch circle diameters PCD2, PCD3 of the inner bearings 50, 60 in the second and third rows from the tool side are made smaller than pitch circle diameters PCD1, PCD4 of the outer bearings 40, 70 in the first and fourth rows. Contact angles α2, α3 of the inner bearings 50, 60 in the second and third rows from the tool side are made smaller than contact angles α1, α4 of the outer bearings 40, 70 in the first and fourth rows. |
